A Modeling Method for Oxygen-Enriched Regeneration System of Light Hydrocarbon Cracking Catalyst

Abstract

This invention belongs to the field of light hydrocarbon catalytic cracking technology and discloses a modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst. The regeneration system modeling method includes: establishing a kinetic model of coke combustion and fuel combustion reactions; mathematically modeling the coking process in the regenerator and establishing a coking rate equation; establishing a steady-state model of the regeneration system and calculating the contents of CO, CO2, H2O, and O2 in the flue gas, as well as the coke content of the regenerated catalyst; performing a heat balance calculation of the regeneration system to obtain the temperature of the regenerator outlet stream; and optimizing the regeneration system objectives, specifically optimizing the catalyst regeneration effect and the oxygen content of the outlet flue gas. The method proposed in this invention can simulate, predict, and optimize the oxygen-enriched regeneration process of light hydrocarbon cracking, providing guidance for practical operation.

Description

Technical Field

[0001] This invention relates to the field of light hydrocarbon catalytic cracking technology, and in particular to a modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst. Background Technology

[0002] Ethylene and propylene are important petrochemical products, mainly obtained through the thermal and catalytic cracking of hydrocarbons. With the development of relevant catalysts, the catalytic cracking of light hydrocarbons has become a technology with great development potential in recent years. The catalytic cracking of light hydrocarbons generally employs a flow-cycle technology. The catalyst and light hydrocarbon feedstock are mixed and reacted in the reactor, and after separation at the outlet by gas-solid separation equipment such as a cyclone separator, the catalyst is sent to a regenerator for coke burn-off regeneration. The regenerated catalyst is then recycled back to the reactor inlet.

[0003] Catalytic cracking is an endothermic reaction, with the heat required for the reaction provided by combustion in the regenerator, using the catalyst as a medium to supply heat to the reactor. However, in the catalytic cracking of light hydrocarbons, the amount of coke formed on the catalyst is relatively small, and the heat of combustion is insufficient to maintain the reactor temperature. Therefore, additional fuel needs to be added in the regenerator. This fuel consumption is the bottleneck of energy consumption in the catalytic cracking process, and reducing fuel consumption can significantly reduce the energy consumption of the catalytic cracking unit.

[0004] On the other hand, ethylene and propylene, as the main products of light hydrocarbon catalytic cracking, are typically supplied with a cryogenic unit (cold box) after the reactor to separate light components such as hydrogen and methane. In conventional regeneration processes, air is the main airflow into the regenerator. Under high-temperature conditions, nitrogen reacts to form nitrogen oxides. A small amount of these nitrogen oxides is adsorbed by the catalyst and ultimately carried by the reaction products to the subsequent cold box unit. In the low-temperature environment of the cold box, nitrogen oxides react with ethylene to form nitroplastics, which accumulate in the cold box. If the temperature of the cold box rises, the nitroplastics will decompose, potentially leading to an explosion.

[0005] CN 114492066 A proposes a modeling method and apparatus for a catalytic cracking oxygen-deficient regeneration system. A kinetic model of the coking reaction is established and corrected using the oxygen-deficient regeneration system, improving the accuracy of predicting the composition of the regenerated flue gas and the carbon content of the catalyst.

[0006] CN 113742935 A proposes a modeling method and apparatus for a two-stage regeneration system in catalytic cracking. By modeling the regenerator, a kinetic model of the catalytic cracking regeneration process can be provided, and the composition of the regeneration flue gas and the dilute phase temperature within the regenerator can be predicted.

[0007] CN 114818359 A proposes a modeling method and apparatus for a catalytic cracking flue gas regeneration system. By establishing a coke combustion reaction kinetic model and a flue gas regeneration system model, the contents of CO, CO2, H2O, and O2 in the regenerated flue gas, as well as the coke content of the regenerated catalyst, are calculated. An optimization module for carbon dioxide enrichment and the regeneration effect of the catalyst to be regenerated is also provided.

[0008] The above models are all based on traditional catalytic cracking technology and do not involve light hydrocarbon cracking. There is currently no research on modeling light hydrocarbon cracking and regeneration systems.

[0009] To address the issues of high fuel consumption and the risk of nitrogen oxide explosions in light hydrocarbon cracking processes due to external fuel replenishment, this invention proposes a modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst. This method aims to solve these problems and provide optimization guidance for actual production. Summary of the Invention

[0010] The purpose of this invention is to provide a modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst, which aims to reduce fuel consumption in the light hydrocarbon cracking regeneration process while improving the safety of the light hydrocarbon cracking process.

[0011] The technical solution of this invention is as follows: A modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst, specifically as follows:

[0012] Establish kinetic models for coke combustion and fuel combustion: considering only the coke and hydrogen combustion reactions, establish reaction rate equations for coke combustion and fuel combustion with respect to carbon, hydrogen, and oxygen concentrations;

[0013] Establish a steady-state model for the regeneration system: Based on the oxygen-enriched regeneration process of light hydrocarbon cracking catalyst, establish a steady-state model for the regeneration system, and calculate the contents of CO, CO2, H2O, and O2 in the flue gas, as well as the coke content of the regenerated catalyst; wherein, a portion of the circulating flue gas is mixed with the main air as circulating gas and enters the regenerator;

[0014] Heat balance of regeneration system: The heat balance of the regenerator combustion process is calculated according to the law of conservation of energy to obtain the temperature of the regenerator outlet stream.

[0015] Target optimization of regeneration system: Target optimization of catalyst regeneration effect and oxygen content in outlet flue gas is carried out to provide a reference for process design.

[0016] In the aforementioned coke combustion reaction kinetic model and fuel combustion reaction kinetic model, reaction rate equations are established for the two reactions of coke combustion and fuel combustion respectively:

[0017] The reaction equation is as follows:

[0018] (1): C + 0.5O2 → CO

[0019] (2): C + O2 → CO2

[0020] (3): H + 0.25O2 → 0.5H2O

[0021] (4): CO + 0.5O2 → CO2

[0022] Two reaction rate equations were established for the dense phase and dilute phase regions of the regeneration system, respectively; the two reaction rate equations for the dense phase region are as follows:

[0023] The reaction rate equation for coke combustion is as follows:

[0024]

[0025]

[0026]

[0027] r: reaction rate, kmol / (m 3 ·s); k j : Reaction rate constant, j is 1-6; σ: Molar ratio of CO2 and CO generated in the dense phase region; ρ P Catalyst particle density, kg / m³ 3 ;ε D : Porosity of the bed in the dense phase region; w C,D : Coke mass fraction of catalyst in the dense phase region; M C : Relative atomic mass of carbon; M H : Relative atomic mass of hydrogen; q: Hydrogen-to-carbon molar ratio of coke; c i : The molar concentration of component i, where the components include CO, CO2, H2O, and O2, in kmol / m 3 ;

[0028] Subscripts: C represents coke, F represents fuel, 1-4 represent reaction equation numbers, D represents dense phase region, and S represents dilute phase region;

[0029] The reaction rate equation for fuel combustion is as follows:

[0030]

[0031]

[0032]

[0033] p: the hydrogen-to-carbon molar ratio of the fuel; w F,D : Fuel mass fraction of the catalyst in the dense phase region;

[0034] The above coke combustion reaction and fuel combustion reaction only consider reaction equations (1)-(3). Reaction equation (4) is the common reaction of both, and its rate equation is as follows:

[0035]

[0036] In the dilute phase region, no combustion reaction of coke and fuel occurs; only the oxidation reaction of CO occurs, i.e., reaction equation (4). Therefore, the reaction rate equation in the dilute phase region is as follows:

[0037]

[0038] The reaction rate constant k j0 Pre-exponential factor; E j0 Activation energy, J / mol; R: Ideal gas constant, 8.314 J / (mol·K); T0: Reference regeneration temperature, K; Molar ratio of CO2 and CO generated in the dense phase region. T: Temperature, K; Porosity of the dense phase bed layer v g,D Volumetric flow rate of gas in the dense phase region, in m 3 / s; A: Regenerator cross-sectional area, m 2 The molar concentration of component i n i : Molar flow rate of component i, kmol / s.

[0039] The steady-state model of the regenerative system includes the following steps:

[0040] For the dense phase region, the molar flow rates of each gas composition at the inlet are shown below:

[0041]

[0042] The molar flow rate of component i at the inlet of the dense phase region, kmol / s; Molar flow rate of component i in the main wind, kmol / s; α: flue gas recirculation ratio; The molar flow rate of component i at the outlet of the dilute phase region, kmol / s;

[0043] For the dense phase region, the equations for the variation of the molar flow rate of each gas component along the axis are as follows:

[0044]

[0045]

[0046]

[0047]

[0048] Z = z / Z D or z / Z S Z D : Dense phase region height, m; Z S : Height of the rare phase region, in meters;

[0049] For the dilute phase region, the molar flow rate of each gas component at the inlet is equal to the molar flow rate of each gas component at the outlet of the dense phase region, as shown below:

[0050]

[0051] The molar flow rate of component i at the inlet of the dilute phase region, kmol / s; The molar flow rate of component i at the outlet of the dense phase region, kmol / s;

[0052] For the dilute phase region, the equations for the variation of the molar flow rate of each gas component along the axis are as follows:

[0053]

[0054]

[0055]

[0056]

[0057] For the flue gas exiting the dilute phase zone, part of it enters the dense phase zone inlet as recirculated flue gas, and part of it is emitted as flue gas, as shown below:

[0058]

[0059] The molar flow rate of component i in the flue gas, kmol / s;

[0060] The heat balance calculation of the regeneration system includes the following steps:

[0061] The heat balance equation is as follows:

[0062]

[0063] C p Heat capacity, kJ / (kg·K), Q loss Heat loss, kW.

[0064] The formula for calculating the heat released during the reaction process is shown below:

[0065]

[0066] H: Heat of reaction, kJ / kmol.

[0067] The objective function for optimizing the regeneration system is:

[0068]

[0069] The operating conditions of the regeneration system are adjusted to optimize the objective function. The flue gas composition and the carbon content of the regeneration catalyst are obtained from the following formula:

[0070] The mole fraction of each component in the flue gas is calculated by the following formula:

[0071]

[0072] y i : The mole fraction of component i in the flue gas;

[0073] Based on the internal configuration of the regenerator, the regenerator is a fully mixed-flow reactor;

[0074] The carbon content of the regenerated catalyst is calculated based on the law of conservation of mass, as shown in the following formula:

[0075]

[0076] F cat Mass flow rate of the catalyst to be produced, kg / s; w out : Coke mass fraction of regenerated catalyst; w in : Mass fraction of coke from the catalyst; F fuel Fuel mass flow rate, kg / s.

[0077] A modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst, implemented based on a modeling device for such a system, includes:

[0078] The regeneration system reaction kinetics model module includes reaction rate equations for coke combustion and fuel combustion.

[0079] The steady-state model module for the regeneration system is used to calculate the contents of CO, CO2, H2O, and O2 in the flue gas, as well as the coke content of the regeneration catalyst.

[0080] The heat balance module of the regeneration system performs heat balance calculations on the combustion process of the regenerator according to the law of conservation of energy, and obtains the temperature of the regenerator outlet material.

[0081] The regeneration system target optimization module optimizes the carbon content of the regeneration catalyst and the oxygen content of the flue gas.

[0082] A modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst is proposed, implemented using programmable software. This software must possess the mathematical calculation capabilities involved in the aforementioned model.

[0083] The beneficial effects of this invention are as follows: This invention provides a modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst. It can provide a reaction kinetic model of the light hydrocarbon catalytic cracking regeneration process, predict the contents of CO, CO2, H2O, and O2 in the flue gas, as well as the coke content of the regenerated catalyst, and obtain the temperature of the regenerator outlet stream. It enables targeted optimization of the regeneration effect of the regenerator catalyst and the oxygen content of the outlet flue gas, providing a reference for process design, reducing fuel consumption in the light hydrocarbon cracking regeneration process, and improving the safety of the light hydrocarbon cracking process. Attached Figure Description

[0084] Figure 1 This is a schematic diagram of the process flow of the oxygen-enriched regeneration system for light hydrocarbon cracking catalyst in this invention.

[0085] Figure 2 This is a schematic diagram of the modeling device for the oxygen-enriched regeneration system of the light hydrocarbon cracking catalyst in this invention. Detailed Implementation

[0086] To make the purpose, content and inventiveness of this invention clearer, the invention will be described clearly and completely below.

[0087] The following is a detailed description of the modeling method for the oxygen-enriched regeneration system of light hydrocarbon cracking catalyst provided by the present invention.

[0088] This invention proposes a modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst, comprising the following steps:

[0089] (1) Establishing a kinetic model for coke combustion and a kinetic model for fuel combustion: The main elements in coke and fuel are carbon and hydrogen, so only the coke combustion and hydrogen combustion reactions are considered, and the influence of other elements is ignored. Establishing reaction rate equations for coke combustion and fuel combustion with respect to carbon, hydrogen and oxygen concentrations.

[0090] During the combustion process in the regenerator, the regeneration system is mainly divided into a dense phase region and a dilute phase region, and the reaction processes in different regions are different. Therefore, the model proposed in this invention establishes reaction rate equations for the dense phase region and the dilute phase region respectively.

[0091] In the dense phase region, four reactions occur: complete and partial oxidation of carbon, oxidation of hydrogen, and oxidation of carbon monoxide. The reaction equations are as follows:

[0092] (1): C + 0.5O2 → CO

[0093] (2): C + O2 → CO2

[0094] (3): H + 0.25O2 → 0.5H2O

[0095] (4): CO + 0.5O2 → CO2

[0096] Since two types of combustion reactions, coke and fuel, occur in the dense phase region, the reaction rates differ for each type of combustion reaction. Therefore, rate equations for the coke combustion and hydrogen combustion reactions of coke and fuel are established separately in the dense phase region.

[0097] The reaction rate equation for coke combustion is as follows:

[0098]

[0099]

[0100]

[0101] r: reaction rate, kmol / (m 3 ·s); k j : Reaction rate constant, j is 1-6; σ: Molar ratio of CO2 and CO generated in the dense phase region; ρ P Catalyst particle density, kg / m³ 3 ;ε D : Porosity of the bed in the dense phase region; w C,D : Coke mass fraction of catalyst in the dense phase region; M C : Relative atomic mass of carbon; M H : Relative atomic mass of hydrogen; q: Hydrogen-to-carbon molar ratio of coke; c i : The molar concentration of component i, where the components include CO, CO2, H2O, and O2, in kmol / m 3 Subscripts: C represents coke, F represents fuel, 1-4 represent reaction equation numbers, D represents dense phase region, and S represents dilute phase region;

[0102] The reaction rate equation for fuel combustion is as follows:

[0103]

[0104]

[0105]

[0106] p: the hydrogen-to-carbon molar ratio of the fuel; w F,D : Fuel mass fraction of the catalyst in the dense phase region;

[0107] The above coke combustion reaction and fuel combustion reaction only consider reaction equations (1)-(3). Reaction equation (4) is the common reaction of both, and its rate equation is as follows:

[0108]

[0109] In the dilute phase region, no combustion reaction of coke and fuel occurs; only the oxidation reaction of CO takes place, i.e., reaction equation (4). Therefore, the reaction rate equation in the dilute phase region is as follows:

[0110]

[0111] In the above formula, some parameters can be calculated using the following formula:

[0112] k j0 Pre-exponential factor; E j0 : Activation energy, J / mol; R: Ideal gas constant, 8.314 J / (mol·K); T0: Reference regeneration temperature, K; T: Temperature in the dense phase region, K; Porosity of the bed in the dense phase region. v g,D Volumetric flow rate of gas in the dense phase region, in m 3 / s; A: Regenerator cross-sectional area, m 2 ; n i : Molar flow rate of component i, kmol / s.

[0113] (2) Establish a steady-state model of the regeneration system: Based on the oxygen-enriched regeneration process of light hydrocarbon cracking catalyst, establish a steady-state model of the regenerator and calculate the contents of CO, CO2, H2O, and O2 in the flue gas and the coke content of the regenerated catalyst.

[0114] The gas composition in the regenerator mainly includes CO, CO2, H2O, and O2. The changes in gas composition in the dense and dilute phase regions are calculated separately based on the reaction kinetic model. The changes in inlet and outlet gas composition are then obtained through the overall regeneration system model.

[0115] The process flow of the regeneration system is as follows: Figure 1 As shown, the flue gas exiting the dilute phase zone can be divided into two parts: flue gas and recirculated flue gas. One part is directly discharged from the system as flue gas, while the other part, the recirculated flue gas, can be mixed with the main air and enter the regenerator. The flue gas recirculation system can not only maintain the fluidization within the regenerator but also reduce heat loss.

[0116] For the dense phase region, the molar flow rates of each gas composition at the inlet are shown below:

[0117]

[0118] The molar flow rate of component i at the inlet of the dense phase region, kmol / s; Molar flow rate of component i in the main wind, kmol / s; α: flue gas recirculation ratio; The molar flow rate of component i at the outlet of the dilute phase region, kmol / s;

[0119] For the dense phase region, the equations for the variation of the molar flow rate of each gas component along the axis are as follows:

[0120]

[0121]

[0122]

[0123]

[0124] Z = z / Z D or z / Z S

[0125] Z D : Dense phase region height, m; Z S : Height of the rare phase region, m

[0126] For the dilute phase region, the molar flow rate of each gas component at the inlet is equal to the molar flow rate of each gas component at the outlet of the dense phase region, as shown below:

[0127]

[0128] The molar flow rate of component i at the inlet of the dilute phase region, kmol / s; The molar flow rate of component i at the outlet of the dense phase region, kmol / s;

[0129] For the dilute phase region, the equations for the variation of the molar flow rate of each gas component along the axis are as follows:

[0130]

[0131]

[0132]

[0133]

[0134] For the flue gas exiting the dilute phase zone, part of it enters the dense phase zone inlet as recirculated flue gas, and part of it is emitted as flue gas, as shown below:

[0135]

[0136] The molar flow rate of component i in the flue gas, kmol / s;

[0137] (3) Heat balance of regeneration system: Heat balance of regenerator combustion process is performed according to the law of conservation of energy.

[0138] The feed stream into the regenerator consists of the catalyst to be regenerated, main air, and fuel; the feed stream out of the regenerator consists of the regenerated catalyst and flue gas. During combustion in the regenerator, heat is released from the combustion of coke and fuel. Some heat loss occurs during this process. The heat balance equation is as follows:

[0139]

[0140] C p Heat capacity, kJ / (kg·K), Q loss Heat loss, kW.

[0141] The formula for calculating the heat released during the reaction process is shown below:

[0142]

[0143] H: Heat of reaction, kJ / kmol

[0144] The temperature of the regenerator outlet stream can be obtained from the heat balance of the regeneration system.

[0145] (4) Optimization of regeneration system objectives: Optimize the regeneration effect of the catalyst in the regenerator and the oxygen content of the outlet flue gas.

[0146] The mole fraction of each component in the flue gas can be calculated using the following formula:

[0147]

[0148] y i : The mole fraction of component i in the flue gas; Based on the assumptions about the interior of the regenerator, the regenerator can be regarded as a fully mixed-flow reactor.

[0149] The carbon content of the regenerated catalyst can be calculated based on the law of conservation of mass, as shown in the following formula:

[0150]

[0151] F cat Mass flow rate of the catalyst to be produced, kg / s; w out : Coke mass fraction of regenerated catalyst; w in : Mass fraction of coke from the catalyst; F fuel Fuel mass flow rate, kg / s.

[0152] During catalyst regeneration, achieving rapid and complete coke combustion requires a certain oxygen flow rate in the inlet main air. However, excessively high oxygen content in the inlet main air will lead to increased oxygen content in the outlet flue gas, resulting in oxygen waste. Therefore, it is necessary to optimize the regeneration process to ensure good catalyst regeneration while avoiding excessive oxygen content in the flue gas. This can be achieved through mathematical programming or intelligent algorithms to optimize the model.

[0153] Based on this, the present invention proposes the following objective function:

[0154]

[0155] The operating conditions of the regeneration system are adjusted to optimize the objective function, and the optimization results provide a reference for process design.

[0156] This invention proposes a modeling device for an oxygen-enriched regeneration system of light hydrocarbon cracking catalysts, corresponding to the above-mentioned modeling method, such as... Figure 2 As shown, the device includes:

[0157] The regeneration system reaction kinetics model module includes reaction rate equations for coke combustion and fuel combustion.

[0158] The steady-state model module of the regeneration system calculates the contents of CO, CO2, H2O, and O2 in the flue gas, as well as the coke content of the regeneration catalyst.

[0159] The heat balance module of the regeneration system performs heat balance calculations on the combustion process of the regenerator according to the law of conservation of energy, and obtains the temperature of the regenerator outlet material.

[0160] The regenerator target optimization module optimizes the carbon content of the regenerated catalyst and the oxygen content of the flue gas.

[0161] A modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst is proposed, implemented using programmable software. This software must possess the mathematical calculation capabilities involved in the aforementioned model.

[0162] The present invention will be further described below with reference to the embodiments. The embodiments are implemented based on MATLAB software, the rate correlation values ​​are empirical values, and the operating parameters are the values ​​of a certain petrochemical experiment.

[0163] Example 1

[0164] The modeling method for the oxygen-enriched regeneration system of hydrocarbon cracking catalyst proposed in this invention is used to optimize the main air oxygen flow rate and flue gas recirculation ratio, so that the catalyst regeneration effect and the oxygen content of the outlet flue gas meet the requirements.

[0165] The regeneration system is set to thermal equilibrium, with a catalyst flow rate of 100 kg / s, a catalyst coke content of 0.5%, a fuel flow rate of 50 kg / s, a regenerator temperature of 750℃, and a pressure of 0.28 MPa. The main air oxygen flow rate is 7 kmol / s, and the flue gas recirculation ratio is 0. Using regeneration system modeling methods, the predicted coke content of the regenerated catalyst is 0.01%, and the oxygen content in the flue gas is 7.00%.

[0166] Example 2

[0167] The regeneration system is set to thermal equilibrium, with a catalyst flow rate of 100 kg / s, a catalyst coke content of 0.5%, a fuel flow rate of 50 kg / s, a regenerator temperature of 750℃, and a pressure of 0.28 MPa. The main air oxygen flow rate is 10 kmol / s, and the flue gas recirculation ratio is 0. Using regeneration system modeling methods, the predicted catalyst coke content is 0.01%, and the oxygen content in the flue gas is 28.26%.

[0168] The difference between this embodiment and Embodiment 1 is that the oxygen flow rate of the main air is increased, and at the same time, due to the excess oxygen, the oxygen content in the flue gas increases.

[0169] Example 3

[0170] The regeneration system is set to thermal equilibrium, with a catalyst flow rate of 100 kg / s and a coke content of 0.5%. The regenerator temperature is set to 750℃ and the pressure to 0.28 MPa. The main air oxygen flow rate is 10 kmol / s. An optimization problem is set up with constraints of a coke content of 0.01% and an oxygen content of 28.26% in the flue gas. The optimized result is a fuel flow rate of 44 kg / s.

[0171] Comparing Examples 1 and 2, increasing the main air oxygen flow rate improved the catalyst regeneration effect, but also increased the oxygen content in the flue gas. Comparing Examples 1 and 3, optimizing the fuel flow rate effectively reduced fuel consumption while keeping other parameters constant.

[0172] In summary, the modeling method for the oxygen-enriched regeneration system of light hydrocarbon cracking catalyst proposed in this invention can simulate and predict the light hydrocarbon cracking and regeneration process, and provide guidance for actual operation through target optimization.

[0173] This embodiment is merely exemplary and not all embodiments. All other embodiments modified or adapted by those skilled in the art are within the scope of protection of this invention.

Claims

1. A modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst, characterized in that, Specifically as follows: Establish kinetic models for coke combustion and fuel combustion: considering only the coke and hydrogen combustion reactions, establish reaction rate equations for coke combustion and fuel combustion with respect to carbon, hydrogen, and oxygen concentrations; Establish a steady-state model for the regeneration system: Based on the oxygen-enriched regeneration process of light hydrocarbon cracking catalyst, establish a steady-state model for the regeneration system, and calculate the contents of CO, CO2, H2O, and O2 in the flue gas, as well as the coke content of the regenerated catalyst; wherein, a portion of the circulating flue gas is mixed with the main air as circulating gas and enters the regenerator; Heat balance of the regeneration system: Based on the law of conservation of energy, a heat balance is performed on the combustion process of the regenerator to obtain the temperature of the regenerator outlet stream; In the aforementioned coke combustion reaction kinetic model and fuel combustion reaction kinetic model, reaction rate equations are established for the two reactions of coke combustion and fuel combustion respectively: The reaction equation is as follows: ； ； ； ； Two reaction rate equations were established for the dense phase and dilute phase regions of the regeneration system, respectively; the two reaction rate equations for the dense phase region are as follows: The reaction rate equation for coke combustion is as follows: ； ； ； : Reaction rate, kmol / (m 3 •s); : Reaction rate constant, j is 1-6; The molar ratio of CO2 to CO generated in the dense phase region; Catalyst particle density, kg / m³ 3 ; Porosity of the bed in the dense phase region; : Coke mass fraction of catalyst in the dense phase region; The relative atomic mass of carbon; The relative atomic mass of hydrogen; The hydrogen-to-carbon molar ratio of coke; : The molar concentration of component i, where the components include CO, CO2, H2O, and O2, in kmol / m 3 ; Subscript: It refers to coke. Indicates fuel. Indicates the reaction equation number. Indicates the dense phase region. Represents the dilute phase region; The reaction rate equation for fuel combustion is as follows: ； ； ； The hydrogen-to-carbon molar ratio of the fuel; : Fuel mass fraction of the catalyst in the dense phase region; The above coke combustion reaction and fuel combustion reaction only consider reaction equations (1)-(3). Reaction equation (4) is the common reaction of both, and its rate equation is as follows: ； In the dilute phase region, no combustion reaction of coke and fuel occurs; only the oxidation reaction of CO takes place, i.e., reaction equation (4). Therefore, the reaction rate equation in the dilute phase region is as follows: 。 2. The modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst according to claim 1, characterized in that, Based on the coke combustion reaction kinetics model, fuel combustion reaction kinetics model, and regeneration system steady-state model, the regeneration system is optimized: the regeneration effect of the catalyst in the regenerator and the oxygen content of the outlet flue gas are optimized to provide a reference for process design.

3. The modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst according to claim 1, characterized in that, The reaction rate constant ; Pre-exponential factor; Activation energy, J / mol; Ideal gas constant, 8.314 J / (mol•K); Reference regeneration temperature, K; the molar ratio of CO2 and CO generated in the dense phase region. ; Temperature, K; Porosity of the dense phase bed ; Volumetric flow rate of gas in the dense phase region, in m 3 / s; : Regenerator cross-sectional area, m 2 The molar concentration of component i , : Molar flow rate of component i, kmol / s.

4. The modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst according to claim 1, characterized in that, The steady-state model of the regenerative system includes the following steps: For the dense phase region, the molar flow rates of each gas composition at the inlet are shown below: ； : Molar flow rate of component i at the inlet of the dense phase region, kmol / s; : Molar flow rate of component i in the main wind, kmol / s; : Flue gas recirculation ratio; : Molar flow rate of component i at the outlet of the dilute phase region, kmol / s; For the dense phase region, the equations for the variation of the molar flow rate of each gas component along the axis are as follows: ； ； ； ； ; : Height of the dense phase region, in meters; : Height of the rare phase region, in meters; For the dilute phase region, the molar flow rate of each gas component at the inlet is equal to the molar flow rate of each gas component at the outlet of the dense phase region, as shown below: ； : Molar flow rate of component i at the inlet of the dilute phase region, kmol / s; : Molar flow rate of component i at the outlet of the dense phase region, kmol / s; For the dilute phase region, the equations for the variation of the molar flow rate of each gas component along the axis are as follows: ； ； ； ； For the flue gas exiting the dilute phase zone, part of it enters the dense phase zone inlet as recirculated flue gas, and part of it is emitted as flue gas, as shown below: ； : The molar flow rate of component i in the flue gas, kmol / s.

5. The modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst according to claim 1, characterized in that, The heat balance calculation of the regeneration system includes the following steps: The heat balance equation is as follows: ； Mass flow rate, kg / s Heat capacity, kJ / (kg•K) Heat loss, kW; The formula for calculating the heat released during the reaction process is shown below: ； Heat of reaction, kJ / kmol.

6. The modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst according to claim 2, characterized in that, The objective function for optimizing the regeneration system is: ； The operating conditions of the regeneration system are adjusted to optimize the objective function; The composition of flue gas and the carbon content of the regenerated catalyst are obtained by the following formula: The mole fraction of each component in the flue gas is calculated by the following formula: ； : The mole fraction of component i in the flue gas; Based on the internal configuration of the regenerator, the regenerator is a fully mixed-flow reactor; The carbon content of the regenerated catalyst is calculated based on the law of conservation of mass, as shown in the following formula: ； : Mass flow rate of the catalyst to be generated, kg / s; : Coke mass fraction of regenerated catalyst; : Mass fraction of coke for catalyst to be generated; Fuel mass flow rate, kg / s.

7. A modeling device for an oxygen-enriched regeneration system based on a light hydrocarbon cracking catalyst, characterized in that, The modeling method for an oxygen-enriched regeneration system of a light hydrocarbon cracking catalyst according to claim 1 includes: The regeneration system reaction kinetics model module includes reaction rate equations for coke combustion and fuel combustion. The steady-state model module for the regeneration system is used to calculate the contents of CO, CO2, H2O, and O2 in the flue gas, as well as the coke content of the regeneration catalyst. The regeneration system heat balance module performs heat balance calculations on the combustion process of the regenerator based on the law of conservation of energy to obtain the temperature of the regenerator outlet stream; the regeneration system target optimization module optimizes the carbon content of the regeneration catalyst and the oxygen content of the flue gas.

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